(a) Technical Field
The present disclosure relates generally to a system and a method for controlling torque intervention of a hybrid electric vehicle. More particularly, the present disclosure relates to a system and a method for controlling torque intervention of a hybrid electric vehicle that divides a request amount of torque reduction by considering a motor state and a ratio of an available reduction range when torque intervention is requested.
(b) Description of the Related Art
As is generally known, a hybrid electric vehicle is driven by an engine which generates torque from fuel combustion and an electric motor which generates torque from an electric battery. The hybrid electric vehicle typically includes a hybrid control unit (HCU) for controlling an engine operation of the hybrid electric vehicle, an engine control unit (ECU) for controlling an operation of an engine, a motor control unit (MCU) for controlling an operation of the driving motor, a transmission control unit (TCU) for controlling an operation of the transmission, and a battery management system (BMS) for managing a condition of a battery. In addition, a traction control system (TCS), which is a safety system for preventing wheel spin and improving driving stability by controlling a brake and an engine while starting out or during acceleration, can be installed in the hybrid electric vehicle.
The hybrid electric vehicle typically performs torque intervention control to divide a request amount of torque reduction into an engine and a motor when the TCU or TCS requests torque reduction. For example, FIG. 1 is a graph showing a conventional method for controlling torque intervention of a hybrid electric vehicle which firstly reduces an engine torque and additionally reduces a motor torque with respect to a shortfall. However, when the torque reduction is continuously requested, a state of charge (SOC) of the battery may be depleted and power performance of the motor may be deteriorated.
FIG. 2 is a graph showing to a conventional method for controlling torque intervention of a hybrid electric vehicle which firstly reduces a motor torque and additionally reduces an engine torque with respect to a shortfall. However, the engine torque is not changed even though torque intervention is requested, engine noise may excessively occur and noise, vibration, and harshness (NVH) performance may be deteriorated.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the disclosure, and therefore, it may contain information that does not form the related art that is already known in this country to a person of ordinary skill in the art.